1. Field of the Invention
The present invention relates to an electric connection casing for use in a car, and more particularly, to an electric connection casing comprising electric circuits, a plurality of relays, fuses, and the like. The electric connection casing is used to perform the branch-connection of a wire harness and an internal circuit thereof comprises electric wires and connection terminals connected with the electric wires under pressure.
2. Description of the Prior Art
Heretofore, the internal circuit of the electric connection casing comprised a bus bar processed by punching a conductive metal plate into a predetermined configuration.
The internal circuit composed of only the bus bar makes it difficult to alter the design thereof. In order to solve this problem, an electric connection casing was proposed and disclosed in Japanese Laid-Open Utility Model Publications Nos. 1-166419 and 2-136989. In this electric connection casing, a circuit comprising electric wires and connection terminals connected therewith under pressure is used as a small intensity-current circuit, which is easy to be design-altered and connected with load electrical components and the bus bar is used as a large intensity-current circuit connected with a power source.
In the electric connection casing comprising the large intensity-current circuit composed of the bus bar and the small intensity-current circuit comprising electric wires and the pressure-contact terminals, it is necessary to accommodate the two circuits having different constructions in one electric connection casing. Thus, the internal construction of the electric connection casing is complicated, and in addition, many kinds of constituent parts are required and moreover, the assembling process is increased because the large intensity-current circuit and the small intensity-current circuit are installed in the electric connection casing in different manners.
Further, the electric connection casing is manufactured at a high cost, because both a punching die mold for forming the bus bar and a wiring die mold for wiring electric wires are required.
In addition, if the large intensity-current circuit connected with the power source is used as parts of other types of cars, it is frequently necessary to alter the design thereof. In this case, it is necessary to alter the construction of the bus bar. Thus, even though only the small-current circuit to be connected with the load electrical components is composed of electric wires and pressure-contact terminals, problems which occur when the large intensity-current circuit is composed of the bus bar cannot be solved.
Heretofore, electric wires were wired in an upper case, a lower case or an insulation plate of the electric connection casing in advance and then, pressure-contact terminals were fixed to the electric wires under pressure. As shown in FIG. 12, the electric wires W to be wired inside the electric connection casing 100 comprise straight portions S and curved portions C.
In wiring the electric wires as described above, the straight portions S can be wired easily but there is a possibility that the curved portions C cannot be easily bent and hence cannot be wired. In this case, it is necessary to bend the electric wires W at large angles or wire the electric wires without bending them. Thus, the electric connection casing has a low degree of freedom in design.
Further, electric wires interfered with each other. As a result, the electric wires cannot be wired.